We know that$$ {1+tan^2{θ}}={sec^2θ}$$$$ {1+cot^2{θ}}={cosec^2{θ}}$$$$ \sqrt {1+tan^2{θ}+1+cot^2{θ}}$$
A clock only with only dots marking 3, 6, 9 and 12 positions has been kept upside down in front of mirror. A person reads the time in the reflection of the clock as 4.50. What is the actual time?
A train moving at speed of 90 km/hr crosses a pole in 7 seconds. Find the length of the train.